Does anyone have any experience estimating tension crack widths for slabs with multiple layers of rebar using ACI 224R?
ACI 224R gives the following equation for estimating crack widths:
However, it doesn't specify what "dc" is. In one location in the document, it defines dc as "thickness of cover from the extreme tension fiber to the closest bar" and in a another location it defines it as "minimum concrete cover to centroid of steel at the tensile face." Issue for me is that once you get multiple layers of bars, the closest bar and the centroid of rebar start to drift away from each other enough that it becomes noticeable in the calculation. Any thoughts?
ACI 224R gives the following equation for estimating crack widths:
However, it doesn't specify what "dc" is. In one location in the document, it defines dc as "thickness of cover from the extreme tension fiber to the closest bar" and in a another location it defines it as "minimum concrete cover to centroid of steel at the tensile face." Issue for me is that once you get multiple layers of bars, the closest bar and the centroid of rebar start to drift away from each other enough that it becomes noticeable in the calculation. Any thoughts?
